Educational information, not medical advice — ask your doctor or midwife.
Kali carbonicum is a homeopathic single remedy made from potassium carbonate, an alkaline mineral salt once known as potash. Homeopaths give it mainly for deep tiredness, weakness and pain in the lower back, and breathing trouble that wakes a person between about 2am and 4am.
It is prepared by serial dilution. The starting salt is diluted over and over, with shaking at each step, so that at the common 30C strength essentially no molecule of the original potassium carbonate is left in the pill.
Its standing inside homeopathy is long and solid, but traditional use is not proof of effect, and controlled trials have not shown homeopathic remedies to do more than placebo (a dummy pill). Read this page as an honest record of how the remedy is used, not as evidence that it treats disease.
Homeopathy is built on a rule of similars: a substance that causes certain symptoms in a healthy person is said to relieve similar symptoms in a sick person once it is heavily diluted. Kali carbonicum was placed with weakness, back pain and night-time breathlessness on that basis.
There is no accepted physical mechanism for this. At 30C nothing of the original salt remains to act on the body, and the idea that water holds a "memory" of it has no support in chemistry or physics.
In trials, people taking homeopathic pills report much the same improvement as people taking placebo. Feeling better after a dose does not show the pill caused the change, since many complaints settle on their own.
Kali carbonicum is sold mainly as small sugar pills (pillules) that dissolve under the tongue. Liquid drops in an alcohol and water base are also common.
Strengths are written as 6C, 30C or 200C, and as 6X or 30X. A higher number means more dilution steps. 30C is the usual over-the-counter choice.
Pills are normally made from lactose (milk sugar) or sucrose. Drops contain alcohol. Check the label if either matters for you or your child.
Potassium carbonate was taken from wood ash for centuries and used in soap, glass and baking. Samuel Hahnemann, the founder of homeopathy, tested it on volunteers and published the results in his Chronic Diseases in the 1820s and 1830s.
It became one of homeopathy's standard mineral remedies and appears in almost every classical materia medica (reference book of remedies). Its reputation rests on those old tests and on case reports passed between practitioners.
Some reactions to Kali carbonicum need urgent care. Call your local emergency number or go to an emergency department straight away — do not wait to see whether it passes.
Call emergency services now if breathing is hard and getting worse, if speaking full sentences is a struggle, if lips or fingertips turn blue, or if a reliever inhaler is not helping. Go to A&E if someone has swallowed raw potash or a caustic product, and do not make them vomit.
See your doctor within a day or two for back pain with numbness, leg weakness or bladder problems, for a cough lasting more than three weeks, for heavy fatigue that does not lift, or for new swelling around the eyes or ankles.
Also see a doctor if you have taken Kali carbonicum for about a week with no change. Lasting symptoms deserve a proper diagnosis.
Evidence grades and traditional-use labels are explained in our methodology. Nothing here is medical advice.
Reviewed by the HealisticMD editorial team How we grade evidence →
The published evidence for Kali carbonicum is weak or absent. That usually means no controlled trial has tested it, not that a trial found it ineffective — the two are different, and we grade only what has been published.
What it is typically used for, usual dose, cautions, and the study behind it where real trial data exists.
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